Diabetes is one of the most serious health issues facing humanity with The World Health Organization reporting that approximately 346 million people worldwide have already been diagnosed with diabetes, making it a global challenge. Diabetes is a chronic disease that manifests when insulin production by the beta cells of the pancreas is insufficient. Type 1 and type 2 diabetes have long been considered diseases resulting from diminished insulin secretion. Research carried out over the past century has more clearly found that generating new beta cells that make insulin is the key to reversing this disease.
Beta cells, which secrete insulin, were discovered in 1869 by a medical student, Paul Langerhans. Pancreatic islets, which are predominately comprised of beta cells, are highly active metabolically, utilizing 20% of the blood supply delivered to the pancreas, but only accounting for 2% of the pancreatic mass; the remainder being extra-islet exocrine tissue containing ductal, acinar and progenitor tissue.
Among type 2 diabetes patients, there is a 50-80% reduction in beta cell mass by the time of diagnosis compared to a reduction in beta mass by 90% or more among type 1 patients, who commonly have an autoimmune component to their beta cell loss. Although the beta cell mass may expand several fold from birth to adulthood, this is not enough to compensate for the greater loss than generation of new beta cells seen in both type 1 and 2 diabetes.
Two recent NIH studies, one in children and adolescents and the other in adults demonstrate that intensive lifestyle interventions designed to improve and impact type 2 diabetes simply have no effect in children and adolescents and cannot be sustained over time among adults. The TODAY Study Group. N Engl J Med. 2012 Apr. 29. [Epub ahead of print]. Diabetes Research Program Prevention Group, Lancet. 2009; 374(9702): 1677-1686. Among children and adolescents with type 2 diabetes, therapy with metformin or lifestyle interventions did not improve diabetes control or the necessity for insulin therapy.
The TODAY study illustrates the need for new insulin-secreting beta cells to delay or prevent the adverse vascular complications of diabetes. Despite the many new treatment and technological armamentariums for diabetes, diabetes-related complications including retinopathy, blindness, neuropathy, amputations, renal insufficiency and dialysis, along with macrovascular complications including heart attack, stroke and peripheral vascular disease have risen among patients with diabetes. For example, recent studies among patients with type 1 utilizing advances including the use of glucose sensors and insulin pumps did not improve hemoglobin A1C levels as much as those seen in the DCCT trial conducted more two decades ago when there were much more limited treatment options. The DCCT Research Group. N Engl J Med. 1993; 329(14):977-986, Bergenstal R M et al, N Engl J Med. 2010; 363(4):311-320. Bergenstal R M, et al, Diabetes Care. 2011; 34(11):2403-2405.
There is a dire need to restore new beta cells and maintain beta cell mass among type 1 and type 2 diabetes. The loss of endogenous insulin is directly correlated with a multiplicity of atherogenic risk factors for microvascular and macrovascular complications. Lack of insulin, which is the hallmark of diabetes results not only in elevated glucose levels, but also results in a large number and wide complexity of metabolic abnormalities. For example, lack of insulin results in diminished activation of lipoprotein lipase resulting in increased levels of triglyceride-rich lipoproteins including chylomicrons and very low-density lipoproteins.
Among type 1 patients the pathology is more complicated, because despite the known autoimmune attack on the beta cells, the delivery of agents to protect the beta cells from further attack has not rendered patients with sustained freedom from exogenous insulin. Despite dozens of clinical trials with a large variety and types of autoimmune therapies that were successful in reversing diabetes in non-obese diabetic (NOD) mice, autoimmune therapy alone provided to patients with type 1 diabetes within 3 months of their diagnosis did not sustain insulin-independence since in man, as compared to mice, there is not the significant beta cell regeneration to sustain insulin independence. Some trials with immune tolerance agents within the first months of diagnosis have rendered 67.5% of patients insulin-free within 7 weeks of therapy, yet over time, all require insulin again.
The leading hypothesis of how new beta cells can be formed in both children and adults is based upon the original works of scientists nearly a century ago who identified that in acute pancreatic injury there is new beta cell growth. Frederick Banting discovered insulin in 1921 by clamping the pancreatic ducts to induce the formation of new pancreatic cells. Dr. Banting collected the pancreatic secretions after acute pancreatic ligation and these secretions became known as insulin. Banting F G and Best C H. J Lab Clin Med. 1922; 7:464-472. This work was supported by several earlier scientists who described that although the population of beta cells is primarily formed during embryogenesis, there is the ability to grow new beta cells post-natally through a process of transformation of ductal cell tissue into insulin-producing tissue. By 1920, the regenerative powers of the pancreas were well described. Frederick Banting attributes his studies leading to the discovery of insulin on the work of Moses Barron who documented that regeneration of injured pancreatic tissue manifests from the pancreatic ducts. Barron M. Surg Gynec Obstet. 1920; 19:437-448. Prior to the widespread availability of insulin, surgeons performed partial pancreatectomies on diabetic children in the hopes of stimulating beta cell regeneration. DeTakats G. Endocrinology. 1930; 14:255-264. Benefits from these novel procedures were described, but were short-lived, likely because of ongoing autoimmune destruction.
Utilizing the data available from the Human Genome Project, this inventor and others have shown the ability to generate fully-functional pancreatic beta cells through the differentiation of non-endocrine cells. The ability of bioactive regions of the Reg gene proteins to transform extra-islet ductal tissue into islets has now been shown by more than a dozen research groups including The Section of Islet Cell and Regenerative Biology at Joslin Diabetes Center at Harvard University and The Departments of Beta Cell Regeneration at the Hagedorn Research Institute in Denmark. The Reg gene peptides identified by this inventor and others are still in development.
This inventor has previously shown that the human Reg gene peptides are directly involved in new beta cell formation from extra-islet ductal tissue. Others have confirmed the presence of Reg in the pancreas of newly diagnosed human diabetes, with subsequent data in both human ductal tissues and from BrdU studies showing that Reg serves to directly form new beta cells from extra-islet ductal tissue. Levetan C S et al, Endocr Pract. 2008; 14(9):1075-1083, Rosenberg L et al, Diabetologia. 1996; 39:256-262, Li J et al, Peptides. 2009; 30(12):2242-2249.
The 15-amino acid hamster Reg3 gamma peptide, first identified in 1983 and identified as being a hamster Reg3gamma peptide in 2007 (Brioche Biopsy's Act 2007, 1769(9-10):579-85), has not been tolerated in man due to the high quantity needed and the production of local side-effects resulting in ⅓ or more of study subjects dropping out of the clinical trials (Dungun K M et al, Diabetes Metal Res Rev. 2009; 25(6):558-565). Previously, this inventor demonstrated that a human Reg3a gene protein has successfully been administered to human pancreatic ductal tissue devoid of islets resulting in a significant increase in insulin concentrations indicating new beta cell formation; a 3-fold rise in total beta cells staining insulin in STZ-rendered diabetic mice was observed. Levetan C S., et al, Endocr Pract. 2008; 14(9):1075-1083. The human Reg3a protein and placebo-treated mice underwent an overnight fast and a fasting glucose level on the morning of day 39 of treatment. Fasting glucose levels were 258.00±84.5 mg/dl in the placebo group compared to a fasting glucose level of 111.00±11.4 mg/dL (P=0.020) in the Reg3a protein-treated mice.
Two studies by separate investigators have shown the ability of Reg peptide to transform human extra-islet pancreatic exocrine tissue into new beta cells in vitro. These studies were conducted by a methodology utilized in pancreatic islet transplantation in which the pancreatic endocrine beta cells are separated from the exocrine ductal tissue; the exocrine ductal tissue was shown to transform into new beta cells in the presence of hamster Reg3gamma peptide. Li J, et al. Peptides 2009; 30:2242-9, Assouline-Thomas B G, Diabetes 2008, 57(Suppl; 1) A2413. The current gold-standard, BrdU labeling, was used to label the beta cell lineage in rodents, which distinguishes whether new beta cells are formed by budding from pre-existing beta cells versus being formed from extra-islet ductal exocrine tissue. Kapur R, et al, Islets. 2012; 4(1).
The Section of Islet Cell and Regenerative Biology at Joslin Diabetes Center found that the 15-amino acid hamster Reg3 gamma peptide was present in the newest beta cells and islets that were formed directly from branching proliferating extra-islet ducts, which also confirms that the mechanism of action of Reg peptide is to form new beta cells from extra-islet exocrine tissue. Guo L et al, Diabetes. 2010, 59(suppl; 1) A2589. When Reg is inhibited by the administration of a blocking antibody in an animal model of pancreatic injury there was attenuated recovery, also confirming that Reg's role is both protective and regenerative during acute pancreatic injury. Viterbo D, et al. JOP. 2009; 10(1):15-23.
The Departments of Beta Cell Regeneration at the Hagedorn Research Institute and Peptide and Protein Chemistry at Novo Nordisk reported a 2-fold increase in the volume of new small islets developing from non-endocrine tissue resulting from the treatment with both the human 14 amino acid Reg3a peptide, HIP, and the 15-amino acid Reg3gamma hamster peptide Kapur R, et al, Islets. 2012; 4(1). Five days after treatment with both the 14-amino acid human Reg3a peptide, HIP, and the 15-amino acid hamster Reg3gamma peptide, INGAP, there were increased levels of new islet markers necessary for islet formation, including NGN3, NKX6.1, SOX9, and INS, indicating that REG is a catalyst for beta cell neogenesis. Kapur R, et al, Islets. 2012; 4(1). Similar to these findings, other data support that the human Reg protein and the hamster Reg3gamma peptide are an initiating factor for downstream regulation of new beta cells. Levetan C., 2010, J Diabetes; 2(2):76-84. For example, when Reg is initially expressed, PDX-1, PAX1, Ngn3, Nkx6.1, Sox9, and Ins are not expressed; once Reg is present, PDX-1, PAX1, Ngn3, Nkx6.1, Sox9 and Ins and other beta cell proliferation factors become present demonstrating that Reg activates downstream factors necessary for beta cell regeneration. Vukkadapu S S Physiol Genomics 2005:21, 201-211, Kapur R., et al., Islets. 2012; 4(1):Epub. Gun and colleagues confirmed positive Reg staining in ductal epithelium in acutely diabetic NOD mice and in the pancreas of a type 1 healthy cadaveric human pancreata or in healthy mice.
The organ specificity of the hamster Reg3 gamma protein to the pancreatic ducts has been illustrated by the tagged Reg3gamma hamster protein labeled with fluorescein isothiocyanate that was administered via intraperitoneal injection to rodents. The only organ that had fluorescent staining was the pancreas with labeling only found specifically to be within the nonendocrine pancreatic ductal populations, again confirming that the mechanism of action of Reg is transformation of extra-islet ductal cells into beta cells. Pittenger G L et al, Diabetologia 2009; 52 (5):735-738. There are now numerous studies confirming that the mechanism of action of the Reg peptides is to transform extra-islet exocrine ductal tissue into new islets rather than the newly formed beta cells resulting from the budding from existing beta cells.
This inventor has also investigated the role and pathways of other human hormones involved in beta cell regeneration with findings consistent with initial findings of Moore and colleagues in 1906, demonstrating the role of gastrointestinal hormones in improving diabetes control among three patients with type 1 diabetes. Levetan C. 2010, J Diabetes; 2(2):76-84, Moore et al, Biochem J. 1906; 1(1): 28-38. The mechanism of action of these gastrointestinal hormones were not only found to be in insulin secretion, but decades later these gut peptides have been shown to be involved in the transformation of extra-islet exocrine tissue into new endocrine tissue containing beta cells. Wang T C. J Clin Invest. 1993; 92(3):1349-56.
Not until 1999, when the use of cell lineage labeling became available, did the embryological concepts of the pancreas change. Whereas it had been thought that the pancreas was derived from both ectoderm and endoderm, it has now been shown that the entire pancreas arises only from endoderm during embryological development. This helps explain how beta progenitor cells have been described as residing diffusely throughout the adult pancreatic tissue and how growth factors transform pancreatic extra-islet ductal tissue into new beta cells. Over the past several decades, the ability to regenerate new beta cells from progenitor cells found within the pancreatic ductal tissue has been illustrated by many teams.
Despite some promise using the hamster Reg3gamma peptide in patients with type 1 diabetes with a 27% rise in stimulated c-peptide among type 1 patients with no detectable c-peptide at baseline, without 1) a tolerable agent that patients are able to use and 2) the usage of an immune tolerance agent combined with any such agent that can increase beta regeneration, an improved impact on insulin requirements is not likely to be sustained in trials (Lipsett M. Cell Biochem Biophys. 2007; 48(2-3):127-3). Data from JJ Meier and colleagues demonstrates that the newest beta cells are the ones that are most vulnerable to cytokine-induced death and trigger autoimmune attack. Meier J J et al Diabetologia 2006; 49(1):83-9.
Despite early findings of patients with type 1 diabetes demonstrating a significant reduction in insulin requirements and improvements in stimulated c-peptide within 54 days of usage among type 1 patients, sustained results have not been seen and very poor tolerability with more than ⅓ of patients receiving such severe skin site reactions not to continue in the trial, further clinical development of optimized versions of the 15 amino acid hamster Reg3gamma peptide have been abandoned. This inventor discloses an optimized 15 amino acid hamster 3gamma peptide that can be further used in combination with an immune tolerance agent to protect newly formed beta cells from autoimmune destruction, for sustained insulin independence.
Some success has temporarily been seen among immune tolerance agents utilized among recent onset type 1 patients, but without new beta cell formation over time, the limited amount (fewer than 10%) of beta cells remaining at the time of type 1 diagnosis will undergo apoptosis until patients require insulin again. Clinical trials using hamster Reg3 gamma alone have concluded that 1) lack of tolerance due to injection site swelling and pain due to the large amount of peptide required 2) lack of sustained efficacy 3) lack of insulin independence have not led to consideration of new formulations of hamster Reg3 gamma that may be more tolerable in man and allowing for lower dosages.
Thus, for hamster Reg3gamma to be successful, both a new formulation that allows for more sustained action with lower amounts of drug are critical for potential success in man that has been seen in animal models. Additionally, regeneration agents alone such as with proton pump inhibitors (lansoprazole) and DPP-4 inhibitors (sitagliptin), which have shown success in mouse models do not reflect the lack of success in man among newly diagnosed type 1 patients who have shown neither long term insulin independence with a regeneration agent or an immune tolerance agent. Certain aspects of the invention, require that the optimized hamster Reg3gamma peptide be used with an immune tolerance agent among type 1 patients and to have the immune tolerance agent on board at the time that new beta cells are being generated.
The immunosuppressive drug Cyclosporine has been shown to have long-term safety and short-term efficacy for rendering new onset patients with type 1 diabetes insulin-independent. The immunosuppressive effects of Cyclosporine were discovered in 1972 in a screening test on immune suppression designed and implemented by Dr. Hartmann Stateline. The success of Cyclosporine in preventing organ rejection was later shown in kidney transplants by Calne and colleagues at the University of Cambridge and in liver transplants performed initially at the University of Pittsburgh Hospital. Cyclosporine was subsequently approved for use in 1983. Since then, it has been used to prevent and treat graft-versus-host reactions in bone marrow transplantation and to prevent rejection of kidney, heart, and liver transplantation.
In addition to transplants, Cyclosporine has also been used in psoriasis, severe atopic dermatitis, pyoderma gangrenosum, chronic autoimmune urticaria, and, infrequently, in rheumatoid arthritis and related diseases. It is commonly prescribed in the US as an ophthalmic emulsion for the treatment of dry eyes. Cyclosporine has also been used to help treat patients with acute severe ulcerative colitis that do not respond to treatment with steroids. This drug is also used as a treatment of posterior or intermediate uveitis with noninfective etiology. Cyclosporine is also currently used to experimentally treat cardiac hypertrophy.
Twenty-five years ago, Bougneres and colleagues reported in the New England Journal of Medicine that among forty children between the ages of 7 and 15 years of age with recent onset type 1 diabetes, 67.5% of patients were able to discontinue insulin within 48±5 days of initiation of 7.5 mg/kg/day of Cyclosporine in two divided dosages. Bourgneres P F. N Engl J Med 1988; 318:663-670). By 12 months after the initiation of Cyclosporine, 50% of patients remained insulin free. Over the next six years of follow-up the initial cohort was pooled with 43 more children with recent onset type 1 diabetes for a total of 83 children given Cyclosporine, who were compared to 47 children with new onset type 1 diabetes during the same time period who were not treated with Cyclosporine. DiFillippo G Diabetes 45:101-104, 1996. Over the first 4 years, the Cyclosporine-treated group kept plasma C-peptide at levels twice as high as the control group (P<0.02). It took 5.8 years for glucagon-stimulated C-peptide to become undetectable in the Cyclosporine group vs. 3.2 years in the control group. Average insulin dose remained lower by 0.2-0.4 units/kg/day. Hemoglobin A1C was lower by 1% in the Cyclosporine-treated group who also had significantly less hypoglycemia than the diabetic control subjects (P<0.05). After four years, the differences between the groups became non-significant. Other studies have found similar data that Cyclosporine had a positive impact on recent onset type 1 diabetes patients, but over time, all patients required insulin. (The Canadian-European Randomized Control Trial Group. Diabetes 1988; 37:1574-82, Assan R. Diabetes Metab Res Rev 2002; 18:464-472, Feutren G. Lancet. 1986 Jul. 19; 2(8499):119-24). In one trial of 285 patients with recent onset type 1 diabetes whom were treated for a mean of 20 months with 7.5 mg/kg/day of Cyclosporine, there were permanent renal side effects seen after following patients for 13 years. Patients in this study received renal biopsies with extensive non-invasive renal follow-up. Even patients with moderate kidney lesions on biopsy at 1 year had normal and stable clearance values at 7 to 13 years (Assan R. Diabetes Metab Res Rev 2002; 18:464-472).
Trials with Cyclosporine fell out of favor because there were no permanent remissions over time. Lack of permanent remission is hypothesized by this inventor to be due to the data suggesting that as in the case of Cyclosporine and more than a dozen other agents over the past decade utilized for protecting the beta cells from further autoimmune attack, the agents are unable to impact the remaining beta cells in the pancreas. It is estimated that fewer than 10% of functioning beta cells remain at the time of diagnosis of type 1 diabetes. Despite trials showing a positive impact of many autoimmune therapies initiated within twelve weeks of symptoms and diagnosis of type 1 diabetes, none have resulted in lasting insulin independence. Immune tolerance agents utilized among recent onset type 1 patients that in addition to Cyclosporine have shown a potential immune benefit but have not resulted in significant or sustained insulin independence include, but are not limited to the heat shock protein 60, Diapep 277, Bacille Calmette-Guérin (also known as the BCG vaccine and commonly known as the vaccine against tuberculosis), mycophenolate mofetil, daclizumab, rituximab (anti CD20), anti CD3 antibodies including hOKT3 gammal (Ala-Ala), and the monoclonal antibody TRX4 (ChAglyCD3), CTLA4-Ig (abatacept) a selective co-stimulation modulator as it inhibits the co-stimulation of T cells, campath-1H, anti-CD52 antibody, a humanized monoclonal antibody to T-cells, polyclonal anti-T-lymphocyte globulin (ATG), GAD antibody vaccine based on the 65 kDa isoform of the recombinant human glutamic acid decarboxylase protein (rhGAD65), diazoxide and Alpha-1 Antitrypsin.
Type 2 diabetes results from a different etiology, but similar to type 1 diabetes there is a substantial loss of 50-75% of beta cell mass at the time of diagnosis; however, the loss is not as acute as that seen from the autoimmune destruction in type 1 diabetes. The beta cell loss seen in type 2 diabetes is due to a more chronic beta cell loss that is impacted by a number of factors including lifestyle, free fatty acids and genetics. Thus, while the beta call loss is not due to sudden autoimmune destruction, there is still the need for beta cell regeneration and sustained beta cell mass.
To date, there have been no studies that combine an immune tolerance agent with a known beta cell regeneration growth factor that has been shown to directly stimulate the formation of new beta cells from ductal cells. One of the reasons that this combination of an immune tolerance agent with a Reg peptide is that it has not previously been considered and has not been obvious is because dozens of preclinical trials with rodent type 1 diabetes models including NOD mouse models have shown only the need for gastrin and other beta cell growth factors for reversal of diabetes. Likewise, rodent type 1 diabetes models including NOD mouse models have shown that using an immune tolerance agents alone is all that is needed to reverse type 1 diabetes in mice.
This inventor has shown great distinctions between the insulin-producing islets of mice and men with humans having much more complex islet structures with respect to composition of cell type, neural and vascular innervation and unique paracrine interactions that are not found in rodents. Levetan has demonstrated vast differences in the islets of mice and men, which may explain the many, many studies conducted among rodent models in the field of diabetes that later are unable to be replicated in human studies. Levetan C S et al. Endocr Pract. 2012; 27:1-36. [Epub ahead of print]. Specifically, trials with multiple different agents and types of agents have been utilized in preclinical rodent models evaluating agents that may be successful in clinical practice for usage in patients with type 1 diabetes. This inventor has also previously shown, like many other scientific teams, that after fetal development of beta cells, typically new beta cells are only derived from the existing, surviving beta cell population. Different and unique to the previous art in the field, this inventor has shown the ability to post-natally generate new beta cells by the transformation of human pancreatic ductal tissue. Levetan C. J Diabetes. 2010; 2(2):76-84, Levetan C S. Endocr Pract. 2008; 14(9):1075-83.
New and unique research by this inventor, which has not been obvious in the prior art, is 1) the ability to reverse diabetes in the diabetic mouse models may be flawed by the complexity of the human islet compared to that of the rodent and 2) the process of generating new beta cells must be from a different source than from the beta cells remaining after the diagnosis of type 1 or type 2 diabetes is made because of the limited supply (<10% for type 1 diabetes and <50-75% for type 2 diabetes). This inventor has shown the ability to transform new pools of beta cells within new islets from extra-islet ductal tissue (See U.S. Pat. Nos. 8,211,430, 7,989,415, 7,714,103 and 7,393,919).
There is a need in the art for new therapeutic modalities for the treatment of diabetes in humans that generate new beta cells from extra-islet tissue while preserving the population of nascent beta cells from destruction by the immune system.